MESA (microsurgical epididymal sperm aspiration) is performed for men with vasal or epididymal obstruction (s/p vasectomy, congenital bilateral absence of the vas deferens). It is done under an operating microscope in the operating room and usually coordinated with a woman’s egg retrieval. MESA can retrieve a large quantity of sperms and is very safe compared to other sperm retrieval techniques. This allows for an extensive collection of sperms to be cryopreserved for future use in IVF.
During MESA a needle is inserted through the scrotal skin into the testis and then the epididymis is dissected. The fluid that flows from the ducts of the epididymis is aspirated and sent for laboratory examination to identify sperms. The sperms are then used for IVF ICSI. The sperms that are not used for ICSI can be cryopreserved for future In-Vitro Fertilization (IVF) cycles with a female partner.
A recent prospective observational study of couples with obstructive azoospermia that underwent IVF-TESA-ICSI showed that fresh MESA cycles resulted in improved embryo cleavage, blastulation and implantation rates. In addition, serum antisperm antibody titers decreased significantly following MESA.
The TESA procedure has also been reported to be associated with adverse testicular histomorphometric changes, including apoptosis and tubular damage. Apoptosis has been attributed to the needle pricking that occurs during a TESA. TUNEL staining of ipsilateral caudal and carpus epididymis after a TESA showed an upregulation of the apoptosis pathway. It is thought that apoptosis is due to the inflammatory response to the needle prick and subsequent disruption of the Leydig cell population. mesa tesa